JP2000133451A - Manufacture of organic electroluminescent element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for an organic electroluminescent element capable of enhancing its production efficiency and reducing its cost. SOLUTION: This manufacturing method for an organic electroluminesent element includes a process to form a thin film layer 10 containing at least a luminescent layer 6 organic compound on a first electrode 2 formed on a substrate 1 and a process to form a second electrode 8 on the thin film layer 10, and production efficiency can be enhanced by simultaneously forming (n) pieces (n) is 2 or larger integers} of at least either one of the thin film layers 10 or the second electrodes 8 on the substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device, a flat panel display, a backlight, a lighting, an interior, a sign, a signboard, an electrophotographic device, and the like.
The present invention relates to a method for manufacturing an organic electroluminescent device capable of converting electric energy into light.

[0002]

2. Description of the Related Art In recent years, researches on organic electroluminescent devices in which electrons injected from a cathode and holes injected from an anode recombine in an organic phosphor sandwiched between both electrodes to emit light have been actively conducted. It has become. This device has attracted attention because it is thin, emits light with high luminance under a low driving voltage, and emits multicolor light by selecting a fluorescent material.

[0003] It has been shown for the first time that an organic electroluminescent device emits light at high brightness at a low voltage by CWTang et al. Of Eastman Kodak Company (Appl. Phys. Lett., 51 (12) 913 (198).
7).). A typical configuration of the organic electroluminescent device shown here is a hole-transporting diamine compound by a vapor deposition method, 8-hydroxyquinoline aluminum as a light emitting layer, on a glass substrate on which an ITO transparent electrode film is formed, Mg: Ag was sequentially provided as a cathode, and green light emission of 1000 cd / m ² was possible at a driving voltage of about 10 V. Although the current organic electroluminescent device has a different configuration such as providing an electron transport layer in addition to the above-described device components, it basically follows the configuration of CWTang et al.

[0004] The use of these organic electroluminescent devices capable of emitting high brightness and multicolor light for display devices and the like has been actively studied. In the case of a full-color display, red (R) and green ( G) and blue (B) light emitting layers are formed. Conventionally, such pattern processing has been achieved by a wet process typified by a photolithography method, but the organic film forming the organic electroluminescent element has poor durability against moisture, organic solvents, and chemicals. It is also disclosed that a device capable of a wet process can be obtained by devising an organic material as typified by JP-A-6-234969. However, in such a method, the organic material used for the device is limited. Will be done. Further, there is a similar problem in pattern processing of an electrode on an organic layer necessary for a display element.

For these reasons, an organic electroluminescent element is often manufactured by a dry process typified by a vapor deposition method, and is realized by using a mask vapor deposition method for pattern processing. That is, a shadow mask is arranged in front of the substrate of the element, and an organic layer or an electrode is deposited only on the shadow mask opening.

Further, as a patterning method without using a wet process, Japanese Patent Application Laid-Open Nos. 5-275172, 5-25859, and 5-258860.
There is known a partition method disclosed in, for example, Japanese Patent Application Laid-Open Publication No. HEI 9-26139. A stripe-shaped partition wall arranged in parallel on the substrate after the first electrode patterning is prepared, and a light emitting material and a second electrode material are deposited on the substrate in a direction perpendicular to the partition wall and in a direction oblique to the substrate surface. This is a method of patterning. In the partition method disclosed in Japanese Patent Application Laid-Open No. H8-315981, vapor deposition is performed vertically on a substrate having a T-shaped cross section or a partition wall having an overhang portion in which part or all of the cross section has an inverse taper. Then, the second electrode is patterned.

[0007]

The thin-film layer including the light-emitting layer and the second electrode formed on the thin-film layer go through working steps in a vacuum apparatus both when using the mask deposition method and when using the partition wall method. It is essential that these steps become factors that determine the productivity of the light emitting device and have a significant effect on the production cost of the device. The present invention solves such a problem, and provides a method for manufacturing an organic electroluminescent device that can improve device productivity and reduce costs.

[0008]

According to the present invention, there is provided a process for forming a thin film layer including a light emitting layer comprising at least an organic compound on a first electrode formed on a substrate, and forming a second electrode on the thin film layer. A method of manufacturing an organic electroluminescent device including a step of forming, wherein at least one of the thin film layer and the second electrode is simultaneously formed on n (n is an integer of 2 or more) substrates. This is a method for manufacturing an organic electroluminescent device.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The organic electroluminescent device of the present invention is a device in which at least a light emitting layer made of an organic compound exists between an anode and a cathode, and emits light by electric energy.

The method for producing an organic electroluminescent device of the present invention comprises:
At least one of the thin film layer and the second electrode is formed simultaneously on n (n is an integer of 2 or more) substrates. On the substrate to be used, the first electrode or the first electrode and a spacer at least partially having a height exceeding the thickness of the thin film layer are formed. This manufacturing method is applied to an organic electroluminescent element having an arbitrary structure regardless of the type of a light emitting device such as a single light emitting element, a segment type, a simple matrix type, an active matrix type, and the number of light emitting colors such as color and monochrome. It is possible.

In the present invention, after the formation of the first electrode or the formation of the first electrode and the spacer corresponding to m (m is an integer of 2 or more) organic electroluminescent elements is performed on one substrate, m
In a vacuum step of forming a thin film layer including a light-emitting layer and a second electrode by cutting and separating into n pieces, a method of simultaneously processing n pieces (n is an integer of 2 or more) can be used.

The step of forming the first electrode and the step of forming the spacer are processing by photolithography, and include applying a photosensitive component, pattern exposure through a photomask,
Development is carried out by etching using a photosensitive component pattern and, if necessary, removing the photosensitive component pattern.

After formation of the first electrode, a spacer can be formed on the substrate at least partially having a height greater than the thickness of the thin film layer. This spacer functions as a partition in the partitioning method, or functions as a layer for preventing a shadow mask from damaging a thin film layer in a mask evaporation method, defines a light emitting region, and covers an edge portion of the first electrode. Can function as an insulating layer.

M sheets (m is an integer of 2 or more) on one substrate
The patterning of the first electrode corresponding to the organic electroluminescent element is performed by using a photomask having a pattern prepared in an arrangement corresponding to the m first electrode patterning on one photomask, and exposing and developing. It can be performed in the steps of ITO etching and resist removal. Or 1
After preparing a photomask corresponding to the first electrode patterning for the number of sheets, patterning m first electrodes by repeating exposure through this photomask m times, and then developing,
It can be performed by various procedures such as performing an ITO etching and a resist removal step. As described above, it is preferable that the substrate on which the m first electrodes are formed or the first electrode and the spacer are formed on one substrate be cut into m substrates and then subjected to a subsequent manufacturing process.

According to the first electrode patterning, a thin film layer including at least a light emitting layer made of an organic compound and a second electrode are formed to form an organic electroluminescent device. In the present invention, at least one of the thin film layer and the second electrode has n sheets (n is 2).
(The above integers) are simultaneously formed on the substrate. When a thin film layer is formed, it is not limited to forming all the constituent layers on n substrates. For example, the hole transport layer is formed on n substrates at the same time. The light emitting layer may be formed on one substrate each. The same applies to the case where the second electrode includes a plurality of layers.

The formation of the thin film layer or the second electrode is performed by a dry process, and the operation is performed in a vacuum device.
In order to make the operation proceed efficiently, it is preferable to set n substrates at the same time in a vacuum apparatus and perform a manufacturing process for the n organic electroluminescent elements in one vapor deposition process.
Since the number of constituent functions formed by a dry process, such as the formation of a thin film layer, the formation of a second electrode, and the formation of a protective layer, is large, adopting a method of processing n sheets at a time is an efficient method of manufacturing an organic electroluminescent device. Can be

The patterning method of the light emitting layer and the second electrode is not limited, and a partitioning method may be used, but it is preferable to pattern at least one of them by a mask vapor deposition method. Selection of a step using the mask evaporation method can be performed in accordance with the function of the light-emitting element to be formed. For example, in a monochrome light emitting element,
The step of forming the second electrode is appropriate. In a color display, mask deposition can be performed in one of the steps, and the other can be performed by a partition wall method, or both can be performed by a mask deposition method. Further, even when the patterning of the second electrode is performed by the partition method, a shadow mask is often used in combination to regulate the deposition area.

The patterning method of the second electrode is not limited, and known techniques such as a partition wall method, a mask vapor deposition method, and a laser ablation method can be used. Among them, a mask vapor deposition method which can cope with a wide range of electrode forming conditions is preferable. .

In the mask vapor deposition method, a shadow mask in which an opening corresponding to a target patterning and a mask portion are formed is arranged on the front surface of a substrate, and each material is vapor deposited.
In the present invention, a method of patterning at least one of a light emitting layer and a second electrode in a state in which n shadow masks are arranged on n substrates, respectively, and a method of attaching the mask to a frame having n openings. It is preferable to use a method of patterning at least one of the light emitting layer and the second electrode using the shadow mask.

Since the shadow mask itself often has insufficient rigidity and mechanical strength, it usually has the same size,
It is used by attaching it to a frame made of a material having sufficient mechanical strength. In the present invention, a method of manufacturing an organic electroluminescent element by patterning at least one of the light emitting layer or the second electrode in a state where n shadow masks attached to a frame are arranged for each of n substrates. It is preferably used. This is referred to as a “split type”. In this case, since n independent shadow masks are used, the degree of freedom of mask replacement is large, and the masks can be individually positioned, so that highly accurate patterning is possible.

Another preferred method is "shoji type".
Can be called. That is, at least one of the light emitting layer and the second electrode is patterned using a shadow mask attached to a frame having n openings. N on shadow mask
Since the relative positions of the surfaces are determined at the time of manufacturing the mask, the n substrates can be relatively moved and the respective substrates can be aligned. The use of this type of shadow mask has the advantages that the strength of the entire mask is improved and that the number of processed substrates can be increased by reducing the size of the substrate.

Whether to use the "split type" or the "shoji type" is determined by the size of the organic electroluminescent device to be manufactured, the number of devices to be formed simultaneously, the definition of each device, the type of device, and the like. It is decided in consideration of. Since each has the above-mentioned characteristics, it is preferable to select such characteristics.

According to the present invention, an organic electroluminescent device is manufactured by simultaneously forming at least one of a thin film layer including a light emitting layer or a second electrode on n (n is an integer of 2 or more) substrates. However, the procedure for manufacturing the element and the method and material used are 1
This is exactly the same as in the case of producing each surface. FIGS. 1 and 2 show a plan view and a cross-sectional view of a typical structure of an organic electroluminescent device to be formed. On a transparent first electrode (anode) 2 formed on a glass substrate 1, a hole transport layer 5, a light-emitting layer 6, an electron transport layer 7, and a second electrode (cathode) 8 are laminated. Further, a protective layer may be formed on the second electrode.

In the present invention, the first electrode may be patterned into a plurality of striped electrodes arranged at a predetermined interval, and the second electrode may be patterned into a plurality of striped electrodes intersecting the first electrode. Preferably, the intersection of the first electrode and the second electrode becomes a light emitting region, and a matrix is formed. The angle of intersection between the first electrode and the second electrode is not limited, but is often orthogonal.

When the process is performed until the second electrode patterning of the organic electroluminescent element is performed and the organic electroluminescent device is taken out to the atmosphere, the light emission characteristics are deteriorated due to moisture and oxygen in the outside air. In order to prevent this, it is preferable that a protective layer is simultaneously formed on n substrates after the second electrode forming step.

As the material of the protective layer, inorganic materials such as silicon oxide, gallium oxide, titanium oxide and silicon nitride, various polymer materials, and organic materials constituting an organic electroluminescent element can be used. Among them, silicon nitride is a suitable protective layer material having excellent barrier properties against moisture. These protective layers are formed by an evaporation method, a sputtering method, a CVD method, or the like. However, depending on a material to be used, the protective layer can be formed by patterning by a known method such as a mask evaporation method. Further, the light emitting region may be sealed using a known technique.

In the present invention, it is preferable to form the first electrode by patterning the ITO film into a plurality of striped electrodes arranged at intervals, but m sheets (m is 2) on one substrate In order to form a first electrode corresponding to an organic electroluminescent device having the above (integer), it is preferable to pattern one substrate in an arrangement divided into m, further form a spacer, and thereafter cut into m sheets And separate.

The first electrode and the second electrode serve to supply a sufficient current for light emission of the device, and at least one of them is desirably transparent to extract light. Usually, the first electrode formed in contact with the substrate is a transparent electrode, and this is an anode.

Preferred transparent electrode materials include tin oxide,
Zinc oxide, indium oxide, vanadium oxide, indium tin oxide (hereinafter ITO) and the like can be given. For the purpose of patterning, it is preferable to use ITO having excellent workability.

In the step of patterning the first electrode, a photolithography method involving wet etching can be used. The pattern shape of the first electrode is not particularly limited, and an optimum pattern may be selected depending on the application. In the present invention, it is preferable to perform patterning on a plurality of striped electrodes arranged at regular intervals.

The ITO may contain a small amount of metal such as silver or gold in order to reduce the surface resistance of the transparent electrode or to suppress the voltage drop. In addition, tin, gold, silver, zinc, indium, Aluminum, chromium, and nickel can also be used as ITO guide electrodes. In particular, chromium is a suitable metal because it can have both functions of a black matrix and a guide electrode. From the viewpoint of power consumption of the device, it is desirable that ITO has low resistance. For example, an ITO substrate of 300Ω / □ or less (ITO substrate)
If it is a transparent substrate on which a thin film is formed), it can function as an element electrode. However, at present, it is possible to supply an ITO substrate of about 10Ω / □, and therefore, it is particularly desirable to use a low-resistance product. The thickness of the ITO can be selected according to the resistance value, and is usually 100 to 300 nm. ITO
The film forming method is not particularly limited, such as an electron beam method, a sputtering method, and a chemical reaction method.

The use of the transparent electrode does not cause any major obstacle as long as the visible light transmittance is 30% or more, but ideally, it is preferably close to 100%. Basically, it is preferable to have the same transmittance in the entire visible light range, but if it is desired to change the emission color, it is also possible to positively impart light absorbency. In such a case, it is technically easy to change the color using a color filter or an interference filter.

The material of the substrate is not particularly limited as long as it has optical transparency, mechanical strength, heat resistance and the like suitable for functioning as a display or a light emitting element. Although plastic plates and films such as polymethyl methacrylate, polycarbonate and amorphous polyolefin can be used, it is most preferable to use a glass plate. As the glass material, non-alkali glass, soda lime glass coated with a barrier coat such as a silicon oxide film, or the like can be used. Since the thickness only needs to be sufficient to maintain the mechanical strength, 0.5 mm or more is sufficient.

An antireflection function can be added to the first electrode or the substrate by using a known technique.

Since the spacer is often formed in contact with the first electrode, it is preferable that the spacer has sufficient electric insulation. A conductive spacer can be used, but in that case, an electrically insulating portion for preventing a short circuit between the electrodes may be formed. As the spacer material, a known material can be used. For an inorganic material, an oxide material including silicon oxide, a glass material, a ceramic material, and the like, and for an organic material, a polyvinyl-based, polyimide-based, polystyrene-based, acrylic-based, Preferred examples include polymer resin materials such as novolaks and silicones. Further, by blackening the entire spacer or a portion in contact with the substrate or the first electrode, a function like a black matrix that contributes to an improvement in display contrast of the organic electroluminescent device can be added to the spacer. In such a case, as a spacer material, an inorganic material such as silicon, gallium arsenide, manganese dioxide, titanium oxide or a laminated film of chromium oxide and metal chromium, and an organic material to the above resin material are used to improve the electrical insulation. Known pigments and dyes such as treated carbon black type, phthalocyanine type, anthraquinone type, monoazo type, diazo type, metal complex salt type monoazo type, triallylmethane type, aniline type, or the above inorganic material powder were mixed. Materials can be mentioned as preferred examples.

The method of patterning the spacer is not particularly limited, but a method of forming a spacer layer on the entire surface of the substrate after the patterning step of the first electrode and patterning the spacer layer by a known photolithography method is easy in process. The spacer may be patterned by an etching method using a photoresist or a lift-off method, or a photosensitive spacer material obtained by imparting photosensitivity to the above-described resin material is used, and patterning is performed by directly exposing and developing the spacer layer. You can also.

The thin film layers included in the organic electroluminescent device include: 1) a hole transport layer / light emitting layer, 2) a hole transport layer / light emitting layer / electron transport layer, 3) a light emitting layer / electron transport layer, and 4) And e) a light-emitting layer in which the above-mentioned combined substances are mixed in a single layer. That is, if a light-emitting layer made of an organic compound is present as an element configuration, a light-emitting material alone or a light-emitting material and a hole-transport material or an electron-transport, as described in 4), in addition to the multi-layer structure of 1) to 3) above. Only one light-emitting layer containing a material may be provided.

The hole transporting layer is formed of a hole transporting substance alone or a hole transporting substance and a polymer binder.
As the hole transporting substance, N, N'-diphenyl-N,
N'-di (3-methylphenyl) -1,1'-diphenyl-4,4'-diamine (TPD) and N, N'-diphenyl-N, N'-dinaphthyl-1,1'-diphenyl-
Triphenylamines represented by 4,4'-diamine (NPD), N-isopropylcarbazole, biscarbazole derivatives, pyrazoline derivatives, stilbene compounds, hydrazone compounds, oxadiazole derivatives and phthalocyanine derivatives Heterocyclic compounds, in the polymer system, polycarbonate and polystyrene derivatives having the monomer in the side chain, polyvinyl carbazole, polysilane, polyphenylene vinylene and the like are preferable,
There is no particular limitation.

The material of the light-emitting layer formed by patterning on the first electrode is anthracene, pyrene, and 8-hydroxyquinoline aluminum, for example, bisstyrylanthracene derivative, tetraphenylbutadiene derivative, coumarin derivative, Oxadiazole derivatives,
A distyrylbenzene derivative, a pyrrolopyridine derivative, a perinone derivative, a cyclopentadiene derivative, a thiadiazolopyridine derivative, and a polymer system include polyphenylenevinylene derivatives, polyparaphenylene derivatives, and polythiophene derivatives. As the dopant to be added to the light emitting layer, rubrene, a quinacridone derivative, phenoxazone 660, DCM1, perinone, perylene, coumarin 540, a diazaindacene derivative, or the like can be used as it is.

As the electron transporting substance, it is necessary to efficiently transport electrons from the cathode between the electrodes to which an electric field is applied, and it is desirable to have a high electron injection efficiency and to efficiently transport the injected electrons. . For this purpose, it is required that the material has a high electron affinity, a high electron mobility, a high stability, and a small amount of impurities serving as traps during production and use. As materials satisfying such conditions, 8-hydroxyquinoline aluminum, hydroxybenzoquinoline beryllium,
(4-biphenyl) -5- (4-t-butylphenyl)
Oxadiazole derivatives such as -1,3,4-oxadiazole (t-BuPBD) and oxadiazole dimer derivatives 1,3-bis (4
-T-butylphenyl-1,3,4-oxadizolyl)
Biphenylene (OXD-1), 1,3-bis (4-t-
Butylphenyl-1,3,4-oxadizolyl) phenylene (OXD-7), triazole derivatives, phenanthroline derivatives, and the like.

The above materials used for the hole transporting layer, the light emitting layer and the electron transporting layer can be used alone to form each layer. As the polymer binder, polyvinyl chloride, polycarbonate, polystyrene, poly (N- (Vinyl carbazole), polymethyl methacrylate, polybutyl methacrylate, polyester, polysulfone, polyphenylene ether, polybutadiene, hydrocarbon resins, ketone resins, phenoxy resins, polyurethane resins, and other solvent-soluble resins, phenol resins, xylene resins, petroleum resins,
Urea resin, melamine resin, unsaturated polyester resin,
It is also possible to use the resin dispersed in a curable resin such as an alkyd resin, an epoxy resin, and a silicone resin.

The organic layers such as the hole transport layer, the light emitting layer and the electron transport layer may be formed by resistance heating evaporation, electron beam evaporation, sputtering or the like. Although not particularly limited, an evaporation method such as resistance heating evaporation or electron beam evaporation is usually preferable in terms of characteristics. The thickness of the layer cannot be limited because it depends on the resistance value of the organic layer.
It is selected from between 1000 nm.

The cathode serving as the second electrode is not particularly limited as long as it can efficiently inject electrons into the light emitting layer of the present device. Therefore, it is possible to use a low work function metal such as an alkali metal, but considering the stability of the electrode, platinum, gold,
Preferable examples include metals such as silver, copper, iron, tin, aluminum, magnesium and indium, and alloys of these metals with low work function metals. In addition, a stable electrode can be obtained while maintaining high electrode injection efficiency by doping the organic layer with a small amount of a low work function metal in advance and then forming a film of a relatively stable metal as a cathode. These electrodes are also manufactured by resistance heating evaporation,
Dry processes such as electron beam evaporation, sputtering, and ion plating are preferred.

The electric energy mainly refers to a direct current, but it is also possible to use a pulse current or an alternating current. The current value and the voltage value are not particularly limited. However, in consideration of the power consumption and life of the device, it is necessary to obtain the maximum luminance with the lowest possible energy.

The shadow mask has an opening serving as a deposition portion and a mask portion serving as a non-deposition portion.
In the shadow mask corresponding to the stripe-shaped second electrode pattern, there is a problem that the mask portion becomes thin like a thread and the shape of the opening is deformed by bending or the like. In order to prevent such a problem, a means for improving the strength of the shadow mask by introducing a reinforcing line across the opening to prevent the deformation of the stripe-shaped opening is adopted. The reinforcing line arranged on the shadow mask used for forming the light emitting layer formed in a matrix and the reinforcing line arranged on the shadow mask used for forming the second electrode functioning as a continuous conductive line in a stripe shape are located at the installation positions. However, each is devised so as not to cause any trouble. FIG. 3 shows an example of a shadow mask used for patterning the light emitting layer, and FIGS. 4 and 5 show examples of a shadow mask used for patterning the second electrode. However, the present invention is not limited thereto.

In the shadow mask corresponding to such a fine pattern, the mechanical strength of the mask portion serving as the non-evaporated portion is insufficient, so that the shadow mask corresponding to the n organic electroluminescent elements is formed in one opening. A single shadow mask attached to one frame, or a shadow mask provided with n mask portions in a frame having n openings, as compared with a shadow mask attached to a frame having The method of the present invention using a mask is effective in maintaining the strength and accuracy of the shadow mask, and as a result, increases the production yield of the organic electroluminescent device.

The shadow mask used for the mask vapor deposition method for the light emitting layer and the second electrode is made of a metal-based material such as stainless steel, a copper alloy, an iron-nickel alloy, and an aluminum alloy, and various resin-based materials. There is no particular limitation. When the strength of the mask is not sufficient due to the fine pattern and it is necessary to improve the adhesion of the organic electroluminescent device to the substrate by magnetic force, it is preferable to use a magnetic material as the mask material. Examples of the material include hardened magnet materials such as pure iron, carbon steel, W steel, Cr steel, Co steel, and KS steel, MK steel, Alnico steel, and NKS steel.
Steel, precipitation hardening magnet materials such as Cunico steel, sintered magnet materials such as OP ferrite, Ba ferrite, and various rare earth magnet materials represented by Sm-Co and Nd-Fe-B systems, silicon steel sheets, Al-Fe Alloy, metal core material such as Ni-Fe alloy (Permalloy), Mn-Zn based,
A ferrite core material such as a Ni-Zn or Cu-Zn system, or a dust core material obtained by compression-molding a fine powder such as carbonyl iron, Mo permalloy, or sendust together with a binder. It is desirable to manufacture the mask from a material obtained by forming these magnetic materials into a thin plate shape, but a material obtained by mixing powder of the magnetic material into rubber or resin and forming the film into a film shape can also be used.

The method for producing the shadow mask is not particularly limited, but may be a mechanical polishing method, a sand blast method,
Although a method such as a sintering method or a laser processing method can be used, it is preferable to use an etching method, an electroforming method, or a photolithography method which is excellent in processing accuracy. Among them, the electroforming method is a particularly preferable method for producing a shadow mask since the mask portion can be formed relatively easily.

There are three types of organic electroluminescent devices for full-color display, which are patterned corresponding to three emission colors having emission peak wavelengths in three color regions of red (R), green (G) and blue (B). Having a light-emitting layer. The patterning of one light emitting layer of such a full-color organic electroluminescent device is performed using a shadow mask in which openings are formed at every three pitches of the first electrode. After patterning the light emitting layer of the first color, the relative position between the substrate and the shadow mask is moved by one pitch to produce a light emitting layer of the second color, and the relative position is further moved by one pitch to obtain the third light emitting layer. A color light emitting layer is formed.
However, the formation of the light-emitting layer of the full-color organic electroluminescent device is not limited to this method, and a method of performing mask deposition of one light-emitting layer twice or more may be used.

[0050]

Hereinafter, the present invention will be described with reference to examples.
The present invention is not limited by these examples.

Example 1 A surface of a non-alkali glass having an outer size of 360 mm × 300 mm and a thickness of 1.1 mm having a thickness of 130 mm was formed by sputtering.
An ITO glass substrate (manufactured by Geomatec) on which an ITO transparent electrode film having a thickness of nm was formed was prepared. This ITO film was cut by patterning using a photolithography method. In this manner, a substrate having a size of 46 mm × 38 mm and having an ITO film (first electrode) having a width of 12 mm in the center portion is obtained.
Nine sheets were produced.

The shadow mask for the light emitting layer has a thickness of 0.2 m.
A 15 mm square opening is formed in the center of a stainless steel plate having a width of 2 mm and a stainless steel frame having a width of 2 mm.

The shadow mask for the second electrode has a thickness of 0.2
A stainless steel plate with a width of 2 mm is arranged on a stainless steel plate of 4 mm in size with four openings of size 5 mm × 12 mm spaced at a distance of 2 mm from the center of the mask.

After cleaning the four patterned ITO substrates, they are set in a vapor deposition machine, the degree of vacuum is set to 2 × 10 ⁻⁴ Pa or less, and the shadow mask for the light emitting layer is arranged on the front surface of each substrate, and adhered to each other. I let it. In this state, the thickness of the copper phthalocyanine was 20 nm as indicated by a film thickness monitor using a quartz oscillator,
N, N'-diphenyl-N, N'-dinaphthyl-1,
1'-diphenyl-4,4'-diamine (NPD) 10
0 nm and Alq ₃ 100 nm were deposited. afterwards,
The thin film layer was doped with lithium vapor by doping (equivalent to a thickness of 0.5 nm).

Next, the shadow mask was replaced with the second electrode shadow mask, and aluminum was applied at a degree of vacuum of 3 × 10 ⁻⁴ Pa or less.
The second electrode was patterned by evaporation to a thickness of 0 nm.

As a result, four substrates each having four green light-emitting elements on the substrate can be processed simultaneously.

Example 2 As shown in FIG. 3 (FIG. 3 of ELX-2), a shadow mask having a mask portion and a reinforcing line formed on the same plane was prepared for use in patterning the light emitting layer. The outline of one shadow mask is 120 × 84 mm, and the thickness of the mask portion 31 is 25.
μm, 272 stripe-shaped openings 32 having a length of 64 mm and a width of 100 μm are arranged at a pitch of 300 μm. Each stripe-shaped opening has a width 2 orthogonal to the opening.
Reinforcing wires 33 having a thickness of 0 μm and a thickness of 25 μm are formed at intervals of 1.8 mm. Each shadow mask is fixed to a stainless steel frame 34 having the same outer shape and a width of 4 mm. The twelve shadow masks produced in this manner are used in three sets of four. In this embodiment, an organic electroluminescent device of a "split type" is manufactured with n = 4.

For the second electrode patterning, four identical shadow masks having a structure in which a gap 36 exists between one surface 35 of the mask portion 31 and the reinforcing line 33 as shown in FIGS. 4 and 5 are prepared. did. The outline of the shadow mask is 1
20 × 84 mm, the thickness of the mask portion is 100 μm, and 200 stripe-shaped openings 32 having a length of 100 mm and a width of 250 μm are arranged at a pitch of 300 μm.
On the mask portion, a mesh-like reinforcing line having a regular hexagonal structure having a width of 40 μm, a thickness of 35 μm, and a distance between two opposing sides of 200 μm is formed. The height of the gap is equal to the thickness of the mask portion and is 100 μm. Each shadow mask is used by being fixed to a stainless steel frame similar to the shadow mask for the light emitting layer.

The first electrode was patterned as follows.
An ITO glass substrate (manufactured by Geomatic) having a 130-nm-thick ITO transparent electrode film formed on the surface of a 1.1-mm-thick alkali-free glass substrate by a sputtering deposition method.
Was cut into a size of 240 × 200 mm. A photoresist was applied on the ITO substrate, and the photoresist was patterned by exposure and development by a normal photolithography method. Since the purpose of this embodiment is to form an organic electroluminescent element with m = 4, it is necessary to perform patterning of the first electrode in an arrangement corresponding thereto, and the photomask used for pattern exposure is composed of four organic electroluminescent elements. The first electrode pattern corresponding to the light emitting element was used. Further, patterning can be performed by repeating pattern exposure for each of the four sheets. After removing unnecessary portions of the ITO by etching, the photoresist is removed, so that the I / Os corresponding to the four organic electroluminescent elements are removed.
The TO film was patterned into a stripe shape having a length of 90 mm and a width of 70 μm. 816 striped first electrodes are arranged at a pitch of 100 μm per sheet.

The spacer was formed as follows. Polyimide photosensitive coating agent (UR-3, manufactured by Toray Industries, Inc.)
100) was applied onto the substrate on which the first electrode was formed by spin coating, and prebaked at 80 ° C. for 1 hour in a nitrogen atmosphere using a clean oven. This coating film is subjected to pattern exposure through a photomask. In this case, as in the case of the above-described first electrode patterning, alignment corresponding to the four organic electroluminescent elements is performed, and one photomask is used. Or, the patterning of the photosensitive coating agent is performed by individually performing pattern exposure. For development, DV-505 manufactured by Toray Industries, Inc. was used, and then baked in a clean oven at 180 ° C. for 30 minutes and further at 250 ° C. for 30 minutes to form a spacer orthogonal to the first electrode. This transparent spacer is 90mm long and 50μ wide.
m, the height is 4 μm, and 201 are arranged at a pitch of 300 μm. The electrical insulation of this spacer was good.

The substrate on which the spacer was formed by patterning the first electrode was cut into four pieces, washed, and set in a vacuum evaporation machine. In the present vapor deposition machine, the substrate and the mask can be aligned with an accuracy of about 10 μm in a vacuum, and the mask can be replaced.

The thin film layer including the light emitting layer was formed as follows by a vacuum deposition method using a resistance wire heating method. In addition,
The degree of vacuum at the time of vapor deposition was 2 × 10 ⁻⁴ Pa or less, and the substrate was rotated with respect to the vapor deposition source during vapor deposition.

First, in the arrangement shown in FIG. 6, copper phthalocyanine was 30 nm and bis (N-ethylcarbazole) was 12
The hole transport layer 5 was formed by vapor deposition on the entire surface of the 0 nm substrate.

Next, four light emitting layer masks are arranged in front of the substrate on which the respective first electrodes and spacers are formed, and they are brought into close contact with each other, and a ferrite plate magnet (manufactured by Hitachi Metals, Ltd.) , YBM-1B). On this occasion,
As shown in FIGS. 7 and 8, the stripe-shaped first electrode 2 is located at the center of the stripe-shaped opening 32 of the shadow mask, the reinforcing line 33 matches the position of the spacer 4, and the reinforcing line and the spacer It is arranged to be in contact.
The four shadow masks are individually positioned with high accuracy. In this state, 0.3 wt% of 1,3,5,7,8-
Pentamethyl-4,4-difluoro-4-bora-3a, 4
8-hydroxyquinoline-aluminum complex doped with a-diaza-s-indacene (PM546) (A
lq ₃ ) was evaporated to a thickness of 43 nm, and the green light-emitting layer was patterned.

Next, in the same manner as the patterning of the green light-emitting layer, the shadow mask was replaced, four masks for the light-emitting layer were attached, and the first electrode pattern was shifted by one pitch and aligned. 1 wt% of 4- (dicyanomethylene) -2-methyl-6- (julolidylstyryl)
30 n of Alq ₃ doped with pyran (DCJT)
The red light emitting layer was patterned by vapor deposition.

Further, the shadow mask was replaced, the third light-emitting layer shadow mask 4 was attached, and further positioned to one first electrode pattern shifted by one pitch.
4,4′-bis (2,2′-diphenylvinyl) diphenyl (DPVBi) was deposited to a thickness of 40 nm to pattern the blue light emitting layer. The green, red, and blue light emitting layers are arranged for every three stripe-shaped first electrodes, and completely cover the exposed portions of the first electrodes.

Next, in the arrangement as shown in FIG.
DPVBi was deposited on the entire surface of the substrate to a thickness of 70 nm and Alq ₃ to a thickness of 20 nm. Thereafter, the thin film layer was exposed to lithium vapor to dope (0.5 nm in equivalent film thickness).

The second electrode was formed as follows by a vacuum evaporation method using a resistance wire heating method. The degree of vacuum at the time of vapor deposition was 3 × 10 ⁻⁴ Pa or less, and the substrate was rotated with respect to two vapor deposition sources during vapor deposition.

As in the patterning of the light emitting layer, four second electrode masks were arranged in front of the substrate on which the respective thin film layers were formed, and they were brought into close contact with each other, and a magnet was arranged behind the substrate. At this time, as shown in FIGS. 10 and 11, both are arranged so that the spacer 4 coincides with the position of the mask portion 31. The alignment of the four shadow masks was checked individually to improve accuracy. In this state, the second electrode 8 was patterned by depositing aluminum to a thickness of 400 nm. The second electrode is arranged in a direction orthogonal to the first electrode that is patterned into a plurality of stripes arranged at intervals, and is patterned into a plurality of stripes arranged at intervals.

Finally, in the arrangement as shown in FIG. 9, silicon monoxide was deposited on the entire surface of the substrate by a 200 nm electron beam evaporation method to form a protective layer.

70 μm width, 100 μm pitch, 81 pieces
A green light-emitting layer, a red light-emitting layer, and a blue light-emitting layer which are patterned are formed on six ITO stripe-shaped first electrodes, and a stripe-shaped second electrode having a width of 250 μm and a pitch of 300 μm is orthogonal to the first electrode. Four simple matrix type color organic electroluminescent elements in which 200 were arranged were produced. Since the three light emitting regions of red, green, and blue form one pixel, the present light emitting device has a pitch of 300 μm and 272 × 20.
It has 0 pixels.

As is apparent from the present example, the vapor deposition steps required for each patterning can be simultaneously performed on four substrates, and an organic electroluminescent device could be manufactured efficiently.

Example 3 A hole transport layer was formed, and the steps up to patterning the green light emitting layer and the red light emitting layer were performed in the same manner as in Example 2. After that, in the arrangement as shown in FIG.
The electron transport layer 7 also serving as a blue light emitting layer was formed by vapor deposition of 20 nm and Alq ₃ on the entire surface of the substrate. That is, in this example, patterning of the blue light emitting layer was not performed.
Thereafter, the thin film layer was exposed to lithium vapor to dope (0.5 nm in equivalent film thickness).

The subsequent patterning of the second electrode and the formation of the protective layer were performed in the same manner as in Example 2. Four organic electroluminescent elements having 272 × 200 pixels at a pitch of 300 μm as in Example 2 could be simultaneously manufactured.

The light emitting area of the manufactured light emitting device was 70 × 2
Emitted uniformly in independent colors of green, red and blue at a size of 50 μm.

By repeating this embodiment, four steps are performed for each process.
Although the organic electroluminescent device could be manufactured one by one, one shadow mask was damaged in the middle, but the operation could be repeated by replacing only the shadow mask.

Example 4 The procedure was the same as in Example 2 up to the formation of the electron transport layer. In the formation of the second electrode, is formed orthogonal to the first electrode,
By using 201 spacers having a pitch of 300 μm as barriers in the barrier rib method, aluminum was vapor-deposited in regions where the barriers were present, and second electrode patterning was performed.
Subsequent formation of the protective layer was performed in the same manner as in Example 1 to obtain four organic electroluminescent elements. As described above, a plurality of organic electroluminescent elements can be obtained at the same time by a relatively simple process, and efficient production becomes possible.

Example 5 The patterning of the first electrode and the formation of the spacer were performed in the same manner as in Example 2, thereby producing a patterned ITO substrate arranged corresponding to m = 4 organic electroluminescent elements.

Three shadow masks for the light emitting layer and one shadow mask for the second electrode were manufactured as “shoji type” as follows.

For patterning the light emitting layer, a mask portion similar to the shadow mask used in Example 1 and a reinforcing line are in the same plane, and the mask portion has a thickness of 25 μm and a length of 64.
mm, 100 μm wide stripe-shaped openings having a pitch of 30
A shadow mask in which 272 pieces of 0 μm were arranged and four faces were formed in almost the same arrangement as the photomask used for patterning the first electrode was produced. The entire outer shape of the shadow mask is 240 × 184 mm, and is fixed to a stainless steel frame having the same outer shape. This frame is 4mm wide to divide the opening vertically and horizontally into two
Is attached (corresponding to the crossbar of a shoji).

Also for the second electrode patterning, the same structure as that used in Example 2 with a gap between one surface of the mask portion and the reinforcing line is used.
A shadow mask in which 200 stripe-shaped openings of m, 100 mm in length and 250 μm in width are arranged at a pitch of 300 μm, and four planes are formed in almost the same arrangement as the photomask used for patterning the first electrode. did.
On the mask portion, a mesh-like reinforcing line having a regular hexagonal structure having a width of 40 μm, a thickness of 35 μm, and a distance between two opposing sides of 200 μm is formed. The entire outer shape of the shadow mask is 240 × 168 mm, and is fixed to a frame having four openings made of stainless steel similarly to the shadow mask for patterning the light emitting layer.

After the ITO substrate on which the first electrode was patterned and the spacers were formed was cut and washed, the substrate was set in a vacuum evaporation machine, and further, a light emitting layer corresponding to the four-sided organic electroluminescent device prepared as described above was formed. Three shadow masks and one shadow mask for the second electrode were set in a vacuum evaporation machine.

The formation of the hole transport layer, the patterning of the green light emitting layer, the red light emitting layer and the blue light emitting layer, and the formation of the electron transport layer were carried out according to Example 2. Further, patterning of the second electrode and formation of the protective layer were performed in the same manner as in Example 2, whereby four organic electroluminescent devices could be simultaneously manufactured. By using this "shoji-type" shadow mask, efficient element manufacture was possible.

[0084]

According to the present invention, there is provided a process for forming a thin film layer including at least a light emitting layer made of an organic compound on a first electrode formed on a substrate, and a second electrode formed on the thin film layer. And forming at least one of the thin film layer and the second electrode on n (n is an integer of 2 or more) substrates simultaneously. An increase in efficiency can be achieved.

[Brief description of the drawings]

FIG. 1 is a plan view showing an example of an organic electroluminescent device manufactured by the present invention.

FIG. 2 is a sectional view taken along the line XX ′ of FIG. 1;

FIG. 3 is a plan view showing an example of a shadow mask for patterning a light emitting layer used in the present invention.

FIG. 4 is a plan view showing an example of a shadow mask for patterning a second electrode used in the present invention.

FIG. 5 is a sectional view taken along the line XX ′ of FIG. 4;

FIG. 6 is a cross-sectional view XX ′ illustrating an example of a method for forming a hole transport layer.
Sectional view.

FIG. 7 is a cross-sectional view taken along the line XX ′ for explaining an example of the light emitting layer patterning method of the present invention.

FIG. 8 is a YY ′ cross-sectional view illustrating an example of a light emitting layer patterning method of the present invention.

FIG. 9 is a cross-sectional view XX ′ illustrating an example of a method for forming an electron transport layer.
Sectional view.

FIG. 10 is a sectional view taken along the line XX 'illustrating an example of the second electrode patterning method of the present invention.

FIG. 11 is a YY ′ cross-sectional view illustrating an example of the second electrode patterning method of the present invention.

FIG. 12 is an XX ′ cross-sectional view illustrating another example of a method for forming an electron transport layer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 1st electrode 4 Spacer 5 Hole transport layer 6 Light emitting layer 7 Electron transport layer 8 Second electrode 10 Thin film layer 11 Hole transport material 12 Light emitting material 13 Electron transport material 14 Second electrode material 30 Shadow mask 31 Mask part 32 Opening 33 Reinforcing line 34 Frame 35 One surface of mask portion 36 Gap

Continued on the front page F term (reference) 3K007 AB02 AB04 AB06 AB18 BA06 BB00 BB06 CA01 CA05 CA06 CB01 DA00 DB03 EB00 FA00 FA01 5C096 AA27 BA04 BC06 CC07 CC23 CH01 EA06 EB13 FA02 FA03 5G435 AA17 BB05 CC09 FF11

Claims (8)

[Claims] A step of forming a thin film layer including at least a light-emitting layer made of an organic compound on a first electrode formed on a substrate; and a step of forming a second electrode on the thin film layer. Wherein at least one of the thin film layer and the second electrode is simultaneously formed on n (n is an integer of 2 or more) substrates. Device manufacturing method. 2. The method according to claim 1, wherein one substrate is cut into m pieces (m is an integer of 2 or more) after patterning the first electrode. 3. A spacer having a height at least a part of which is greater than the thickness of the thin film layer is formed on the substrate before the thin film layer forming step, and one substrate is formed after the spacer forming step.
2. The method for manufacturing an organic electroluminescent device according to claim 1, wherein the substrate is cut into pieces (m is an integer of 2 or more). 4. The method according to claim 1, wherein at least one of the light emitting layer and the second electrode is patterned by a mask deposition method. 5. The organic electroluminescent device according to claim 4, wherein at least one of the light emitting layer and the second electrode is patterned in a state in which n shadow masks are respectively arranged on the n substrates. Manufacturing method. 6. The organic electroluminescent device according to claim 4, wherein at least one of the light emitting layer and the second electrode is patterned using a shadow mask attached to a frame having n openings. Production method. 7. The method according to claim 1, wherein the first electrode is patterned into a plurality of stripe-shaped electrodes arranged at intervals, and the second electrode is patterned into a plurality of stripe-shaped electrodes crossing the first electrode. Item 2. A method for producing an organic electroluminescent device according to Item 1. 8. The method according to claim 1, wherein a protective layer is simultaneously formed on n substrates after the second electrode forming step.